Turbine systems are continuously being modified to increase efficiency and decrease cost. One method for increasing the efficiency of a turbine system includes increasing the operating temperature of the turbine system. To increase the temperature, the turbine system must be constructed of materials which can withstand such temperatures during continued use.
In addition to modifying component materials and coatings, one common method of increasing temperature capability of a turbine component includes the use of cooling channels. Cooling channels are often formed in metals and alloys used in high temperature regions of gas turbines. Typically, these cooling channels are formed through drilling, such as with a laser or waterjet, or electrical discharge machining. However, forming complex cooling channels may be difficult using drilling or electrical discharge machining. Additionally, cooling channels formed through these methods are usually limited to holes extending directly through a wall of the component. While these holes formed directly through the wall provide fluid flow between an inner region and an outer region of the component, they generally do not provide fluid circulation within the walls of the component.
Due to difficulty associated with forming complex cooling channels and the lack of fluid circulation within the walls of the component, various portions of the components, such as the tip portion of a turbine bucket, do not currently include internal cooling channels. Instead, these portions rely on film and/or conductive cooling from cooling channels formed in other portions of the component.